"She gave enough information to us during the course of the interview that probable cause was there to arrest her," said Sheneman.

A massive search for the child, Sandra Cantu, included hundreds of volunteers and law enforcement officials. The search ended April 6 when farmworkers who were draining the irrigation pond to water fields found a suitcase.

Pictures of the girl with dark brown eyes and light brown hair were posted all over Tracy, a city of 78,000 about 60 miles east of San Francisco.

The slain girl's aunt, Angie Chavez, said in a phone interview with The Associated Press early Saturday that she was happy to learn of the arrest.

"I want to know why she did it, if she did it," Chavez said.

Huckaby previously told a local newspaper that Sandra visited her home March 27, the day she disappeared. Huckaby also said she had left her suitcase in the driveway that day, and that it was missing.

Huckaby is the granddaughter of Pastor Clifford Lawless, whose Clover Road Baptist Church was the subject of a police search. Huckaby taught Sunday school at the church.

Huckaby's family had been questioned at length during the investigation, and their homes and vehicles had been searched, Sheneman said.